Few horizontal wells have been completed in unconsolidated formations. Most operators have completed their horizontal wells in consolidated formations using slotted liners to provide borehole stability and a limited amount of sand control. In a recent application in a friable sandstone, pre-packed screens were successfully used in open-hole horizontal well completions. Gravel packing, the industry's preferred sand control method for vertical and deviated wells, has rarely been applied in horizontal wells.
Previous work showed that low-viscosity carrier fluids such as water could completely pack short horizontal model wells, but there are potential drawbacks for field applications. They may require the use of low gravel concentrations, longer placement times, and larger carrier fluid volumes. In permeable formations, excessive fluid loss can occur, damaging the formation. Gravel settling in the tubing during pumping is another concern.